Roll temperature control system



June 10, 1958 E. A. COUDRIET ROLL TEMPERATURE CONTROL SYSTEM 2 Sheets-Sheet 1 Filed Sept. 15, 1955 INVENTQR EDWARD A. COUDRIET 2 Sheets-Sheet 2 E. A. COUDRIET ROLL TEMPERATURE CONTROL SYSTEM R 0 mm v m u 0 C A 0& mm @m m w o i E %34 8 2. g Q. v N A V l 8 R 4 qw mo 9 June 10, 1958 File d Sept. 15, 1955 'heat treatment.

United States Drier rolls are used to heatwebs of paper and other materials as they pass over the rolls, in order to dry ink on the, paper, for example, or forother purposes of The rolls should be heated uniformly across. their heating surfaces so that they will impart heat uniformly to the webs passing around'them, and that has long presented a diflicult problem where a heated fluid atent 73cc 1 v P assists atented June 19, 1958 i the helical portions 34 and 36 of tubes 28 and 32, and

thence through the outlet ends 38 and 40 of tubes 28 and 32 into tube 22, which discharges the fiuid'out-of the roll. The same effect is achieved if the above-described flow is reversed.

The fluid heating arrangement for the rolllt'i has the advantage of dividing the incoming heated fluid into a pair of equal streams, one'of which flows in a helical path from one end of the roll body to the other, while the other stream flows in the opposite direction through an equal helical path extending side-by-side with the first helical path. A unit of area of cover 28 across both helices adjacent one end of the roll, and a correspondmg area adjacent the other end of the roll, must have substantially the same average temperatures,because each is exposed to the combined heating action ofone stream of fresh heating fluid entering one of the helical paths, and an equal stream of used heating fluid leaving the other helical path. The average temperature near the is circulated through the interior of the roll for purposes of supplying the necessary heat. The present invention relates to so arranging such circulation that it will improve control and uniformity of distribution of heat across the Working surfaces of a drier roll or the like;

The invention utilizes multiple streams of fluid moving in opposite rotational directions around the roll, which offsets any interference by the moving fluid with the rotation of the roll. While the invention is primarily concerned with heated drier rolls, it is also'applicable to cooling rolls. V

For a better understanding of the invention, reference= middle of the roll is substantially the same as at the ends of the roll, because both streams of fluid at the middle of the roll have a temperature substantially equal to the average temperatures near the ends of the roll.

In order to improve the even heating qualities of the rolllti, the spaces between the outer surfaces of the helical portions 34. and 36 of the tubes 28 and 32, on the one hand, and the interior surface of the metal cover I 16, on the other hand, are filled with highly heat-conductive material, such as aluminum shavings.

Another embodiment of the invention is illustrated in Figure 2, which shows a roll 40 journaled on a pair of I axles 42 and 44. An'inner cylindrical shell 46 is welded is made to the accompanying drawings, in which present preferred embodiments of the invention are'illustrated Inthe drawings:

Figurel shows a section through the axis of a roll embodying the invention;

Figure 2 shows a. like section of a second species of roll embodying the invention.

Figure 3 shows a like section of a third species of roll embodying the invention.

Referring now more particularly to the drawing, and initially to Figure 1, a heater roll 10 is journaled on axles 1'2 and 14 at its opposite ends. The body of the roll consists' of a hollow cylindrical metal cover 16 secured around a pair of end plates 18 and 20 which are welded around the axles 12 and 14 respectively. The outer surface of the cover 16 supports and heats a Web of paper or the.

like trained around the roll.

.The axle 14 has an axial opening therethrough, and atube 22 extends through the opening from the inside to" around a pair of end plates 48 and 50, which in turn are welded around the axles 42 and 44. An interior supporting plate 52 braces the inner end of the axle 42 against the inner shell 46, and a like plate 54 braces the inner inlet end 30 of a tube 32. The tubes 28 and 3.2 are mounted within the roll body and have helical portions 34 and. 36 which are wound sideby-side in a double helix against the inside of the cover'16'across the space between the end plates 18 and Zil. The respective tubes 28 and 32 have outlet ends 38 and 4!} connected to the inner end of the tube 22. In order to cause opposite flow through the helical portions 34 and 36 of the tubes 28 and 32, the helical portion 34 has its inlet end adjacent end plate 20 and its outlet end adjacent end plate 18, While the helical portion 36 has its inlet end adjacent end plate 18 and its outlet end adjacent end plate 20.

A fluid heating medium, such as water or steam, is heated by any suitable means outside of the roll, and is then pumped through the passage 24 into the inlet ends of tubes 28 and 32, thence in opposite directions through end of the axle 44 against the shell 46. A pair of spacer rings 56 and 58 are welded around the outside of the opposite ends of the shell 46, and around the inside of the opposite ends of an outer cylindrical cover 60. A pair of spaced helical strips 62'and 64 are welded between the inner shell 46 and cover 60, forming double helical passages along the inside of the cover 60. Each of the strips 62 and 64 has one end welded to the spacer ring 58, so that one end of the helical passage to the right of the strip 64 terminates adjacent the spacer ring 58, where it is connected to a radially extending tube 66, and one end of'the helical passage to the left of the strip 64 also terminates adjacent the spacer ring 58, where it is connected to a radially extending tube 68. A tube 70 extends axially from the outer end of axle 44 to connect with radial tube 68, and an annular passage 72 extends from the outer end of axle 44 around the outside of tube 70 to connect with radial tube 66. At the other end of the roll 40, the strip'62 terminates short of the spacer ring 58, while the corresponding end of the strip 64 is welded to the spacer ring 56. This has the efiect of connecting the helical passages to the right and left of strip 64 to each other adjacent spacer ring 56.

When a supply of heated fluid is fed into the passage 72 around the outside of the tube '76, such fluid passes through the tube 66 into the right end of the helical passage to the right of the strip 64, and thence passes helically between the strips 62 and 64 along the length of the roll body until it reaches the terminal end of the strip 62 adjacent the spacer ring 56. There the fluid passes around the end of strip 62 and starts back through the helical passage to the left of strip 64, reversing its direction of flow accordingly. When the fluid reaches the right end of the roll body it passes into tube 68 and is withdrawn through tube 70. The operation is substantially the same if the supply and exhaust connections are reversed. In either case, equal streams of fluid move oppositely in a double helix along the length of the roll body, which substantially equalizes the local average temperatures of the cover Gil across the length of the roll body.

Instead of having the oppositely moving spiral streams of fluid side-by-side, as shown in Figures 1 and 2, the two streams can be disposed on opposite sides of the' center of the roll, as shown in Figure 3. The. roll 76 shown in Figure 3 is journaled on axles 78 and 80at its opposite ends. Inner and outer cylindrical shells 82 and 83 are welded around a pair of end plates84 and 86, which in turn are welded around the axles 78 and 80. Interior supporting plates 88 and 90 brace the inner ends of axles 78 and 80 against the inner shell 82. A ring 92 is welded between the shells 82 and 83 to bisect the annular space therebetween. The ring 92. is canted slightly relative to the roll axis so that a central feed pipe 94 extending perpendicular to the roll axis has one end extending through the inner shell 82 on one side of ring 92, and its opposite end extending through the inner shell 82 on the other side of ring 92. Spiral strips 96 and 98 of the same hand and pitch, are welded between While I have illustrated and described present preferred embodiments of the invention, it will be understood that the invention is not limited thereto, but may be variously embodied and practiced within the scope of the following claims.

I claim:

1. A heat-exchange roll, comprising a roll body, means to journal the roll body for rotation about a central axis throughrthe roll body, means forming at least a pair of helical conduits within the roll body adjacent and in heat exchange relation with its periphery, the inclination of the conduits being in the same direction, means defining an inlet fluid passageway at one end of each helical conduit and restricting fluid flow only into the respecthe shells 82 and 83 to create spiral passages of the 9 same hand and size on opposite sides of ring 92, the opposite ends of strip 96 being welded to end plate 84 and ring 92, and the opposite ends of strip 98 being welded to end plate .86 and ring 92. An inlet tube 1% extends axially from the outer end of axle 8t and connects through a tube 102 with the center of feed pipe 94. A valve 104 controls flow through one end of pipe 94 into the inner end of the spiral passage formed by helical strip 96, and a like valve 186 similarly controls flow from the other end of pipe 94 into the inner end of the spiral passageway formed by helical strip 98. The valves 104 and 106 are adjusted to equalize the flow on opposite sides of the roll. a When the flow along the helical strip 96 reaches the end plate 84 it is drawn off through an exhaust pipe 108, which connects with an annular counterbored discharge passage 110 extending through the outer end of axle 80 around the outside of tube 100. In like manner, when the flow along the helical strip 98 (rotationally and axially opposite to the direction of flow along strip 96) reaches end plate 86, it is withdrawn through an exhaust pipe 112, which also connects with the discharge passage 119. The operation is reversed if the supply and exhaust connections are reversed, because then the heat (if the fluid is heated) is greatest adjacent the ends of the rolls, and less near the center of the roll. The temperature dilference between the ends and the center of the roll is limited by the fact that each spiral passageway extends only half the axial length of the roll, and that distance may be relatively small, so that the temperature drop is small.

The tubular construction of the first of the abovedescribed embodiments of the invention is adaptable for use in the second and third of the above-described embodiments of the invention, and the double-shell construction of the second and thirdembodiments of the invention is similarly adaptable for use in the first of the above-described embodiments of the invention. While the illustrated embodiments of the invention are. drierv rolls supplied with high-temperature fluid, the principles of the invention are also applicable to cooling rolls supplied with a low-temperature fluid.

tive conduit with theinlet passageway of the two conduits being located in the roll bodyat relative opposite ends of the respective conduits, and means defining an outlet passageway at the end of each helical conduit opposite the inlet passageway, whereby fluid is fed through one of the helical condiutsin one rotational direction and through the other of the helical conduits in an opposite rotational direction to offset frictional drag on the roll body during rotation of the roll.

2. A heat-exachnge roll as defined in claim 1, wherein the conduits are integral and rotatable with said body with the helices of said conduits in alternate side-by-side heat transfer relation.

3. An apparatus according to claim 2 in which the means for forming helical conduits comprises an inner cylindrical member coaxial with and radially spaced from said roll body and a plurality of spaced helical strips :integrally fixed therebetween.

4. Apparatus according to claim 1, in which the helical conduits are disposed on opposite sides of the middle of the roll body, one fluid passageway being connected to the end of each of said helical conduits nearest the middle of the roll, and another fluid passageway is connected to the'end of each of said ends of the roll.

5. Apparatus according to claim 4 wherein said one fluid passageway connected to the end of each of said conduits at the middle of the roll constitutes the inlet, and a valve in each of said inlet fluid passageways to enable individual control of each conduit.

6. Apparatus according to claim 1, in which said means for forming helical condiuts comprise a plurality of helical'tubes disposed in side-by-side relation.

7. A heat-exchange roll'as defined in claim 1 wherein said conduits extend substantially the length of the roll body with the helices of said conduits in alternate sideby-side heat transfer relation, the inlet passageway for one conduit and the outlet passageway for the other conduit being at one end of the roll body and the outlet passageway of said one conduit and the inlet passageway of said other conduit being at the other end of said roll body.

References Cited in the file of this patent UNITED STATES PATENTS 16,905 Booth Mar. 31, 1857 733,718 Hildebrand July 14, 1903 1,838,943 Huxford Dec. 29, 1931 1,991,432 Valentine et al Feb. 19, 1935 helical conduits nearest the, 

